U.S. patent application number 12/658410 was filed with the patent office on 2011-08-11 for vehicle braking system.
Invention is credited to Thomas Lenz, Dirk Wohltmann, Thomas Wolf.
Application Number | 20110193407 12/658410 |
Document ID | / |
Family ID | 44353126 |
Filed Date | 2011-08-11 |
United States Patent
Application |
20110193407 |
Kind Code |
A1 |
Wohltmann; Dirk ; et
al. |
August 11, 2011 |
Vehicle braking system
Abstract
An improved braking system and brake control method for a
vehicle, in particular a truck, utilizes at least one pressure line
for carrying a medium from at least one pressurized medium source
to a brake device, and a brake pedal for receiving brake commands
from a vehicle driver and for operating a brake line, which can be
connected to the brake device. A pilot control valve with
accompanying measuring capability quantitatively determines the
brake pressure demanded by the vehicle driver.
Inventors: |
Wohltmann; Dirk;
(Birmingham, MI) ; Wolf; Thomas; (Barsinghausen,
DE) ; Lenz; Thomas; (Lehrte, DE) |
Family ID: |
44353126 |
Appl. No.: |
12/658410 |
Filed: |
February 8, 2010 |
Current U.S.
Class: |
303/139 ;
188/152; 303/20 |
Current CPC
Class: |
B60T 8/4818 20130101;
B60T 15/181 20130101; B60T 8/327 20130101 |
Class at
Publication: |
303/139 ;
188/152; 303/20 |
International
Class: |
B60T 8/176 20060101
B60T008/176; B60T 11/10 20060101 B60T011/10; B60T 11/12 20060101
B60T011/12; B60T 11/28 20060101 B60T011/28; B60T 8/1755 20060101
B60T008/1755; B60T 8/32 20060101 B60T008/32 |
Claims
1. A braking system for a vehicle, comprising at least one pressure
line constructed and arranged to carry a pressurized medium from at
least one source of said medium to a brake device, a brake pedal
for receiving brake commands from a driver of said vehicle and for
operating a brake line, said brake line being connectable to said
brake device, and means for quantitatively determining brake
pressure demanded by said driver.
2. The braking system according to claim 1, wherein said means for
quantitatively determining said brake pressure demanded by said
driver includes a pilot control valve having at least one measuring
device.
3. The braking system according to claim 2, wherein said at least
one measuring device is constructed and arranged to output said
brake pressure in the form of electrical signals.
4. The braking system according to claim 2, further comprising a
control unit constructed and arranged to receive and process brake
pressure signals from said at least one measuring device.
5. The braking system according to claim 4, wherein said control
unit incorporates said brake pressure signals into a feedback
control of the operation of said brake device.
6. The braking system according to claim 5, wherein said control
unit simultaneously processes and compares signals representing
brake pressure for vehicle stability control and said brake
pressure signals from said at least one measuring device.
7. The braking system according to claim 6, wherein said signals
representing brake pressure for vehicle stability control represent
an autonomously demanded brake pressure of a brake assist
system.
8. The braking system according to claim 2, wherein said pilot
control valve includes a double check valve and wherein said at
least one measuring device is a pressure sensor, said double check
valve being constructed and arranged to conduct said pressurized
medium from at least one of (i) at least one of said brake line and
a branch line to an outlet line, and (ii) said outlet line to an
outlet assigned to a branch of said branch line, and wherein said
pressure sensor measures pressure in said outlet line.
9. The braking system according to claim 2, wherein said pilot
control valve includes a double check valve and wherein said at
least one measuring device is first and second pressure sensors,
said double check valve being constructed and arranged to conduct
said pressurized medium from at least one of (i) at least one of
said brake line and a branch line to an outlet line, and (ii) said
outlet line to an outlet assigned to a branch of said branch line,
said first pressure sensor being constructed and arranged to
measure pressure in said brake line, and said second pressure
sensor being constructed and arranged to measure pressure in said
branch line.
10. The braking system according to claim 2, wherein said pilot
control valve includes first and second double check valves and
wherein said at least one measuring device is first, second and
third pressure sensors, said first double check valve being
constructed and arranged to conduct said pressurized medium from at
least one of (i) said second double check valve and a branch line
to an outlet line, and (ii) said outlet line to an outlet, said
second double check valve being constructed and arranged to conduct
said pressurized medium from at least one of (i) said brake line
and a second brake line to a connection of said first double check
valve, said first pressure sensor being constructed and arranged to
measure pressure in at least one of said brake line and said second
brake line, said second pressure sensor being constructed and
arranged to measure pressure in said branch line, and said third
pressure sensor being constructed and arranged to measure pressure
in said outlet line.
11. The braking system according to claim 8, further comprising at
least one multi-way valve constructed and arranged to at least one
of open and close at least a part of said branch line, at least one
of said at least one multi-way valve and said pressure sensor being
electrically actuated.
12. The braking system according to claim 9, further comprising at
least one multi-way valve constructed and arranged to at least one
of open and close at least a part of said branch line, at least one
of said at least one multi-way valve and said first and second
pressure sensors being electrically actuated.
13. The braking system according to claim 10, further comprising at
least one multi-way valve constructed and arranged to at least one
of open and close at least a part of said branch line, at least one
of said at least one multi-way valve and said first, second and
third pressure sensors being electrically actuated.
14. The braking system according to claim 2, wherein said pilot
control valve is assigned to a valve arrangement for transmitting
said pressurized medium to a front axle brake device.
15. The braking system according to claim 2, wherein said pilot
control valve is assigned to a valve arrangement for transmitting
said pressurized medium to a rear axle brake device.
16. The braking system according to claim 2, wherein said pilot
control valve is assigned to a tractor safety valve for
transmitting said pressurized medium to a vehicle trailer.
17. The braking system according to claim 2, wherein said pilot
control valve includes a service relay valve actuatable by pressure
transmitted from an outlet line to selectively at least one of
conduct said pressurized medium from a supply line to a trailer
service coupling and discharge said pressurized medium from said
trailer service coupling.
18. The braking system according to claim 1, wherein said means for
quantitatively determining said brake pressure demanded by said
driver includes a pilot control valve and at least one slip
controller and deceleration controller.
19. The braking system according to claim 18, wherein said at least
one slip controller and deceleration controller are constructed and
arranged to (i) perform a comparison of said brake pressure
demanded by said driver against an autonomously demanded brake
pressure of a brake assist system and (ii) effect adjustment of
delivery of said pressurized medium to said brake device based on
said comparison.
20. A vehicle brake control method, comprising the steps of:
transmitting a pressurized medium from at least one source of said
pressurized medium through at least one pressure line to a brake
device of a vehicle; pressurizing a brake line by driver actuation
of a brake pedal of said vehicle; actuating said brake device by
means of pressure in said brake line; and quantitatively
determining brake pressure demanded by said driver.
21. The method according to claim 19, further comprising the steps
of: regulating actuation of said brake device as a function of a
driving condition of said vehicle using a control unit;
transmitting said brake pressure in the form of electrical signals
to said control unit; and using said control unit, receiving and
processing said transmitted signals into feedback control of said
brake device and simultaneously maintaining a control process.
Description
FIELD OF THE INVENTION
[0001] The present invention generally relates to an improved
braking system and method for a vehicle, in particular a truck,
that quantitatively determine the brake pressure demanded by the
vehicle driver.
BACKGROUND OF THE INVENTION
[0002] Known braking systems of the general type under
consideration include at least one pressure line for carrying
compressed air from at least one pressurized compressed air source
to a brake device, and a brake pedal for receiving brake commands
from a vehicle driver and for operating a brake line, which can be
connected to the brake device. Such systems are used in trucks as
well as in other vehicle types.
[0003] Trucks are often equipped with driving assistance systems
that also include systems that actively control braking
performance. With the aid of various sensors, such brake assist
systems register the driving situation at any given time and, in
specific situations, undertake braking operations according to the
evaluation of these data. In each case, this is effected without
active intervention on the part of the vehicle driver. In order to
preclude negative influences on vehicle handling, control of the
braking performance by the brake assist systems is discontinued as
soon as the driver issues a brake command via the brake pedal. In
known systems, the existence of a brake command on the part of the
driver is registered by a pressure sensor, for example, that
monitors the line pressure on the rear axle circuit or the front
axle circuit of the vehicle. If this sensor registers the presence
of a brake pressure, the control is discontinued and the full
pressure controlled by the driver is transmitted to the vehicle
trailer.
[0004] A disadvantage of such known braking systems is that
simultaneous feedback control by the brake assist system and active
braking ordered by the driver is not possible. Likewise, a
quantitative determination of the brake pressure to be transmitted
to the trailer is not possible in such known braking systems.
SUMMARY OF THE INVENTION
[0005] The present invention overcomes disadvantages associated
with conventional braking systems and provides improved
functionality and control response. Generally speaking, as
described in greater detail hereinafter, the braking system
according to embodiments of the present invention includes a pilot
control valve with integral measuring capabilities (e.g., one or
more pressure sensors) that quantitatively determines the brake
pressure demanded by the vehicle driver. With the actual prevailing
brake pressure being known, it can be controlled without, at the
same time, having to discontinue the automatic braking function of
the brake assist system. This results in improved control.
Moreover, since the known brake pressure makes it possible to
transmit an adequate brake pressure to the vehicle trailer system,
the control accuracy of the trailer brake pressure is also
enhanced. Additionally, a cost savings can be realized since air
consumption can be reduced.
[0006] According to an alternative embodiment of the present
invention, the quantitative determination of the brake pressure
demanded by the vehicle driver is effected using a pilot control
valve and slip and/or deceleration controllers assigned
thereto.
[0007] A vehicle brake control method in accordance with an
exemplary embodiment of the present invention includes the steps
of: (i) transmitting a pressurized medium from at least one medium
source through at least one pressure line to a brake device; (ii)
pressurizing a brake line by the operation of a brake pedal by the
vehicle driver; (iii) actuating the brake device by means of the
pressure; and (iv) quantitatively determining the brake pressure
demanded by the driver.
[0008] Still other objects and advantages of the present invention
will in part be obvious and will in part be apparent from the
specification.
[0009] The present invention accordingly comprises the features of
construction, combination of elements, and arrangement of parts
that will be exemplified in the constructions hereinafter set
forth, as well as the various steps and the relation of one or more
of such steps with respect to each of the others, and the scope of
the invention will be indicated in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] For a fuller understanding of the present invention,
reference is had to the following description taken in connection
with the accompanying drawings in which:
[0011] FIG. 1 is a schematic representation of a pilot control
valve with integral pressure sensor in accordance with an
embodiment of the present invention;
[0012] FIG. 2 depicts a further embodiment of a pilot control valve
for regulating pressure in accordance with the present
invention;
[0013] FIG. 3 is a schematic representation of another embodiment
of a pilot control valve for regulating pressure in accordance with
the present invention;
[0014] FIG. 4 is a schematic representation of a tractor safety
valve with integral pilot control valve in accordance with an
embodiment of the present invention;
[0015] FIG. 5 is a schematic representation of a braking system
according to embodiments of the present invention, showing two
possible placements for the tractor safety valve; and
[0016] FIG. 6 depicts brake slip and deceleration controllers used
in accordance with an alternative embodiment of the present
invention to effect the quantitative determination of the brake
pressure demanded by the vehicle driver.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] As stated above, the present invention provides an improved
braking system including a pilot control valve with integral
measuring capabilities that quantitatively determines the brake
pressure demanded by the vehicle driver. The pilot control valve
can be provided on a front axle brake circuit and/or a rear axle
brake circuit of the vehicle tractor and on the brake circuit for a
trailer. Integrating the measuring function into the pilot control
valve makes the vehicle application easier and facilitates
installation and servicing of the system.
[0018] Preferably, the measuring function outputs the brake
pressure in the form of electrical signals. A plurality of known
pressure sensors are suitably designed to measure a pressure and to
convert this into a current or voltage signal. This signal can be
polled by means of electrical lines from the sensors.
[0019] According to an embodiment of the present invention, a
control unit receives and processes the signals corresponding to
the measured brake pressure. Furthermore, the control unit can
process and, where necessary, co-ordinate further signals from
other sensors and areas of the vehicle electronics. These signals
also include signals relayed from the driving safety and brake
assist systems.
[0020] Preferably, the control unit can incorporate the signals
received into a feedback control of the operation of the brake
device. This highlights the advantage of a common control unit. The
information from the brake assist system and further driving
assistance systems are, in this case, combined in the control unit,
where the output brake pressure is likewise received and processed.
It is therefore possible, by means of the brake pressure measured
in the pilot control valve, to form a closed-loop control circuit,
which allows the automatic braking function of the brake assist
system to be maintained, whilst the driver executes a brake command
via the brake pedal.
[0021] Desirably, the control unit also can simultaneously process
brake pressure signals representative of the brake pressures for
stability control of the vehicle (e.g., from the autonomous brake
assist system), and the measured brake pressure signals, which are
representative of the brake pressure demanded by the driver of the
vehicle. This can include a comparison of these signals.
[0022] According to an embodiment of the present invention, the
pilot control valve includes a double check valve and a pressure
sensor, the double check valve being constructed and arranged to
conduct pressurized medium either from the brake line or from a
branch line to an outlet line, and the pressure sensor being
constructed and arranged to determine the pressure in the outlet
line. Since the pressure sensor is assigned to the outlet line, it
is possible to quantitatively determine both the controlled brake
pressure supplied to the braking system from its pressure sources
and the pressure generated by the driver via the brake pedal. These
two pressures each prevail on an inlet of the double check valve.
The double check valve conducts the higher of these two pressures
at any given time to the outlet, where the pressure sensor is
located.
[0023] According to a further embodiment of the present invention,
the pilot control valve includes a double check valve and first and
second pressure sensors. The double check valve is constructed and
arranged to conduct the pressurized medium either from the brake
line or from a branch line to an outlet line, or from the outlet
line to an outlet, which is assigned to a branch of the branch
line. The first pressure sensor is constructed and arranged to
determine the pressure in the brake line and the second pressure
sensor is constructed and arranged to determine the pressure in the
branch line. The use of two pressure sensors in the respective
inlet lines instead of a single pressure sensor in the outlet line
affords the advantage that, irrespective of which of the two
pressures entering the pilot control valve is greater, it is
possible to determine both the pressure of the supply line and the
pressure of the brake line coming from the driver's brake
pedal.
[0024] According to another embodiment of the present invention,
the pilot control valve includes two double check valves and three
pressure sensors. The first double check valve is constructed and
arranged to conduct pressurized medium either from the second
double check valve or from the branch line to an outlet line. The
second double check valve is constructed and arranged to conduct
pressurized medium either from the brake line or from a second
brake line to the connection of the first double check valve. The
first pressure sensor is constructed and arranged to determine the
pressure in the first or second brake line, and the second pressure
sensor is constructed and arranged to determine the pressure in the
branch line. The use of up to three pressure sensors means that the
pressures in the two inlet lines and in the outlet line of the
pilot control valve can be determined simultaneously. A balancing
of this pressure information can be used, for example, to monitor
the functioning of the sensors and/or the valve. The provision of a
second double check valve, which conducts the pressure of either a
first or a second brake line to the first double check valve, makes
it alternatively possible, in addition to the brake line, which is
also described in the other exemplary embodiments, to conduct the
pressure from the second brake line, which is likewise connected to
the driver's brake pedal. The provision of two such brake lines is
advantageous particularly if one of the brake lines fails (possibly
prescribed as safety-relevant).
[0025] At least one multi-way valve constructed and arranged to
open or close at least one part of the branch line can be provided,
the multi-way valve and/or at least one of the pressure sensors
being electrically operated. Preferably, the multi-way valve is a
2/2-way valve. Other types of multi-way valves can be used,
however, depending on the particular application. Like the pressure
sensor(s), the multi-way valves are electrically connected to the
control unit.
[0026] The multi-way valves are operated on the basis of electrical
signals, which are transmitted, in particular, from the control
unit to the multi-way valves. For determining the signals to be
transmitted, the control unit here relies on, among other things,
the electrical signals relayed to the control unit from the
pressure sensors.
[0027] According to a further embodiment of the present invention,
the pilot control valve is assigned to a valve arrangement for
transmitting pressurized medium to a front axle brake device. This
allows the braking performance of the front axle brakes to be
controlled in a manner according to the invention.
[0028] In another embodiment of the inventive braking system, the
pilot control valve is assigned to a valve arrangement for
transmitting pressurized medium to a rear axle brake device. This
allows the rear axle brakes to be controlled in a manner according
to the invention.
[0029] In yet another embodiment, the pilot control valve is
assigned to a tractor safety valve for transmitting pressurized
medium to a vehicle trailer. This allows the brake pressure of a
trailer braking system to be controlled in a manner according to
the invention.
[0030] Integrating a pilot control valve into valve arrangements
such as front axle, rear axle and tractor safety valve arrangements
affords the advantage of being able to prefabricate the respective
valve arrangements, including the pilot control valve, ready for
assembly, which enables them to be fit to the vehicle in a compact
and time-saving manner. This obviates the need for extensive
installation and wiring works during final assembly to the extent
that was necessary with conventional systems.
[0031] According to an embodiment of the present invention, the
pilot control valve includes a service relay valve, which can be
actuated by means of the pressure transmitted from the outlet line,
in order to selectively conduct pressurized medium from a supply
line to a trailer service coupling or to discharge it from there.
The service relay valve allows the trailer service coupling to be
subjected to the pressure of the supply line or to be switched to
zero pressure.
[0032] According to another embodiment of the present invention,
the quantitative determination of the brake pressure demanded by
the vehicle driver is effected using a pilot control valve and slip
and/or deceleration controllers assigned thereto. According to this
embodiment, the pilot control valve does not include any integral
pressure sensors. The closing of the closed-loop control circuit
necessary for uninterrupted working of the automatic braking
function is nevertheless advantageously achieved in that the
signals from slip and/or deceleration controllers assigned to the
pilot control valve are evaluated by means of the control unit. The
elimination of the pressure sensors can lead to salutary cost
savings.
[0033] Referring now to the drawing figures, FIG. 1 depicts a pilot
control valve for regulating pressure with an integral pressure
sensor. The pilot control valve includes two inlets and an outlet.
A brake line 1 and a supply pressure line 3 are connected to the
valve inlets. Brake line 1 carrying medium is connected to a brake
pedal (not shown) such that a pressure is built up in the brake
line in response to the operation of the brake pedal. An outlet
line 5 is connected to the valve outlet. A pressure sensor 9, which
is designed to determine the pressure in outlet line 5, or other
suitable measuring device(s) for quantitatively determining the
brake pressure is assigned to the outlet line.
[0034] The pilot control valve represented in the inventive
embodiment depicted in FIG. 1 further includes a double check valve
7. Double check valve 7 has two inlets and one outlet, the inlets
being connected on the one hand to brake line 1 and on the other to
supply pressure line 3. A branch line 11 branches off from supply
pressure line 3. The pilot control valve further comprises two
2/2-way valves 13, 15, one of which is assigned to supply pressure
line 3 and the other to branch line 11. 2/2-way valve 13 assigned
to supply pressure line 3 has an `NC` configuration, which means
that the valve is normally closed. 2/2-way valve 15 assigned to
branch line 11 has a `NO` configuration, which means that this
valve is normally open. Sensor 9 and 2/2-way valves 13, 15 are
electrically connected via lines 17 to a control unit (not shown).
Double check valve 7 is constructed and arranged so that the higher
of the pressures prevailing on the inlets of the double check valve
is conducted to outlet line 5. Sensor 9 therefore registers either
the pressure of supply pressure line 3 or the driver's brake
pressure of brake line 1, depending on the switching state of
double check valve 7.
[0035] FIG. 2 depicts a further embodiment of a pilot control valve
according to the present invention. Compared to the pilot control
valve embodiment depicted in FIG. 1, the pilot control valve in
FIG. 2 utilizes two pressure sensors 19, 21 to quantitatively
determine the pressure in the pilot control valve, rather than
single sensor 9, which is used to quantitatively determine the
pressure in outlet line 5. Sensor 19 is assigned to brake line 1
connected to the driver brake signal; sensor 21 is assigned to
supply pressure line 3. Both sensors 19, 21, like two 2/2-way
valves 13, 15, are connected by electrical lines 17 to the control
unit and are designed to transmit electrical signals. The pressure
sensors are, here, capable of simultaneously determining the
pressure in brake line 1 and in supply pressure line 3.
[0036] FIG. 3 depicts another embodiment of a pilot control valve
according to the present invention. In the pilot control valve
embodiment shown in FIG. 3, outlet line 5, brake line 1 and supply
pressure line 3 each have sensors 9, 19, 21, respectively, assigned
to them and are constructed and arranged to quantitatively
determine the pressure in known manner. The pilot control valve
depicted in FIG. 3 is supplemented by a further line inlet--in
addition to the first brake line 1, a second brake line 25 is
connected to the pilot control valve. Second brake line 25 is
likewise connected to the brake pedal (not shown), but is supplied
with pressurized medium from another medium circuit. This will be
described in greater detail below with reference to FIG. 5. The
pilot control valve according to FIG. 3 also includes a second
double check valve 23, which has two inlets and one outlet. Brake
lines 1, 25 are each connected to an inlet of double check valve
23, and the outlet of double check valve 23 is connected to an
inlet of double check valve 7.
[0037] In operation, the pilot control valve embodiment depicted in
FIG. 3 will always conduct that pressure which is higher from
double check valve 23 to double check valve 7. This has the
particular advantage that should either brake line fail the other
brake line will ensure a smooth operation and maintain the facility
for braking by the driver. Since the pressures are quantitatively
determined both in brake line 1, in supply pressure line 3 and in
outlet line 5, it is possible to monitor the correct function of
the pilot control valve and/or the braking system.
[0038] FIG. 4 is a diagram of a tractor safety valve with integral
pilot control valve. It can be seen that the pilot control valve,
which is here an integral part, corresponds to the pilot control
valve embodiment depicted in FIG. 3. It should be appreciated,
however, that other pilot control valve embodiments can be
utilized.
[0039] In addition to the pilot control valve, the tractor safety
valve includes a third double check valve 33, which, in turn,
includes two inlets, one of which is connected to outlet line 5 and
the other to a pressure line 27, which is assigned to a handbrake
valve. On the outlet side, the double check valve is assigned to a
service relay valve 35. Third double check valve 33 is constructed
and arranged to conduct either the output pressure of the pilot
control valve or the pressure relayed by handbrake line 27 and to
actuate service relay valve 35 accordingly. Service relay valve 35
is constructed and arranged to selectively conduct pressurized
medium from supply pressure line 3 to a trailer brake line 29, or
to discharge pressurized medium from trailer brake line 29. Trailer
brake line 29 carrying medium is connected to a trailer brake
coupling (not shown). In this exemplary embodiment, supply pressure
line 3 has multiple branches and supplies the pilot control valve,
service relay valve 35 and a trailer supply line 31 with
pressurized medium.
[0040] FIG. 5 is a diagram of a braking system according to
embodiments of the present invention. Pressurized medium is
supplied to the system from a primary supply storage reservoir 37
and a secondary storage reservoir 39. The pressurized medium from
primary storage reservoir 37 is fed to the system via a primary
line 41, whilst the pressurized medium from secondary storage
reservoir 39 is fed to the system via a secondary line 43.
Pressurized medium is fed via lines 41, 43 to a brake pedal 44, a
front axle valve arrangement 45, a rear axle valve arrangement 47
and a distributor valve arrangement 49.
[0041] The braking system shown in FIG. 5 includes a tractor safety
valve 51 with integral pilot control valve. Pressurized medium is
fed to the tractor safety valve through first brake line 1, second
brake line 25 and supply pressure line 3. Supply pressure line 3 is
connected on the one hand to tractor safety valve 51 and on the
other to distributor valve arrangement 49, which is constructed and
arranged to distribute pressurized medium provided from the primary
or secondary storage reservoir 37, 39, to a front axle, rear axle
and/or trailer medium circuit. A further pressure line 56 is
likewise connected to distributor valve arrangement 49, in order to
conduct pressurized medium to at least one rear axle brake device
55. Tractor safety valve 51 is connected by electrical lines 17 to
a control unit 53, which is constructed and arranged to receive
electrical signals from the tractor safety valve and to interpret
and process them as measuring signals. On the outlet side, two
further pressure lines are connected to tractor safety valve 51.
These are trailer supply line 31 and trailer brake line 29.
[0042] In accordance with an alternative configuration of the
braking system, tractor safety valve 51 can be located proximate
rear axle valve arrangement 47. This alternative placement is also
illustrated in FIG. 5 together with the placement described in the
preceding paragraph.
[0043] As discussed above, according to an embodiment of the
present invention, the quantitative determination of the brake
pressure demanded by the vehicle driver can be effected using the
pilot control valve and brake slip and/or deceleration controllers
assigned thereto. In such embodiment, the pilot control valve does
not include integral pressure sensors. The signals from the slip
and/or deceleration controllers assigned to the pilot control valve
are evaluated by means of the control unit--permitting the closure
of the closed-loop control circuit for uninterrupted functioning of
the automatic braking function. More particularly, referring to
FIG. 6, the pressure-related information is fed into brake slip
controller 60, which is included in control unit 53, and/or
deceleration controller 61 of the autonomous brake assist system.
Based on a comparison of the measured brake pressures with the
brake pressures calculated and/or requested by the brake assist
system, brake pressure adjustments can be implemented using 2/2-way
valves 13 and 15.
[0044] A vehicle brake control method in accordance with an
exemplary embodiment of the present invention includes the steps
of: (i) transmitting a pressurized medium from at least one medium
source through at least one pressure line to a brake device; (ii)
pressurizing a brake line by the operation of a brake pedal by the
vehicle driver; (iii) actuating the brake device by means of the
pressure; and (iv) quantitatively determining the brake pressure
demanded by the driver.
[0045] A further embodiment of the inventive method includes the
additional steps of: (i) regulating actuation of the brake device
by a control unit as a function of the driving situation of the
vehicle; (ii) outputting the measured brake pressure in the form of
electrical signals and transmitting the signals to the control
unit; and (iii) receiving and processing the transmitted signals
into the feedback control of the brake device by means of the
control unit whilst simultaneously maintaining the control
process.
[0046] It will thus be seen that the objects set forth above, among
those made apparent from the preceding description, are efficiently
attained, and since certain changes may be made in the above
constructions without departing from the spirit and scope of the
invention, it is intended that all matter contained in the above
description or shown in the accompanying drawings shall be
interpreted as illustrative and not in a limiting sense.
[0047] It is also to be understood that the following claims are
intended to cover all of the generic and specific features of the
invention herein described and all statements of the scope of the
invention which, as a matter of language, might be said to fall
therebetween.
* * * * *